My family (2 adults and 2 kids - 5 and 7) picked Kennett Square for a weekend trip and found this very charming apartment with a lot of character going on. Walking distance from the downtown area, this unit is on a very quiet street (or at least it *was* quiet until my kids got there...) with plenty of restaurants and shops within a ten minute walk.
Longwood Gardens is probably the area's main attraction, but certainly not the only one. We visited the Delaware Museum of Natural History and the American Helicopter Museum - all within a half hour drive. Great for my boys.
As for the unit itself, there was a comfortable amount of room for 4. The beds were soft, the linens were clean, and the full size kitchen was perfect for us. Recently updated, it had plenty of glassware and utensils, but (if I'm going to nitpick) there could have been a few more pots and pans. This is by no means a mark against it, but if you plan to cook a big dinner, you might want to come prepared.
Very glad to have been able to stay here and would recommend to a friend.